1. Field of Invention
The present invention relates to print ribbons and in particular, to features for print ribbons and structures to form such features.
2. Related Art
Line matrix and other types of impact printing systems utilize print ribbons to transfer images, such as letters and characters, onto media or paper. The print ribbons hold ink so that hammers striking the print ribbon can transfer corresponding ink images to the paper. The print ribbon is typically mounted on a hub and spool assembly, where the ribbon is moved across the printing area to another hub and spool assembly. The ribbon continues reversing direction until the ink is sufficiently depleted to replace or re-ink the ribbon. However, in order for a more efficient use of the print ribbon, the ribbon reversal should not occur until the ribbon is at or near its end. This way, more of the ribbon is utilized.
One conventional method of detecting when the end of a ribbon is reached for ribbon reversal is to use a conductive feature, such as a diagonal line, at the ends of the ribbon. Ribbon reversal in a printer occurs when this conductive feature on the ribbon is detected, such as when the conductive feature shorts between two ribbon posts. However, metallized conductive leaders exhibit life problems due to adhesion of the metallized component to the ribbon fabric while sewn metal thread is difficult to work with and expensive.
Therefore, there is a need for a print ribbon feature that overcomes the disadvantages discussed above.